Insulin is produced either in bacteria (E. coli) or yeast. In the case of bacteria the insulin (expressed as pro-insulin) is produced in inclusion bodies which after denaturation, refolding and renaturation is purified by several steps. Normally several chromatography steps are combined with filtration steps, enzymatic cleavage of pro-insulin to insulin, precipitation crystallization and formulation steps. In the case of a yeast expression system no inclusion bodies are formed, besides this the process is quite similar to the bacterial one.
Insulin is produced at several tons a year and the use of insulin is increasing for every year. More and more people will get diabetes, not the least in the developing world. The increase in demand of insulin makes it necessary to utilize efficient production methods and processes. Yield is ever important and a method giving a higher yield normally gives a better process economy, translating to a more affordable product. The affordability is a key parameter in making the product available to a broader base of patients. This is also important so one does not put an unnecessary constraint on a healthcare sector that is suffering under an increase cost pressure.
Thus, it would be desirable to have a faster, more economic method for insulin production giving a pure product in high yield.
Chromatography purification of insulin using shell beads has not been suggested before.